(1) Field of the Invention
This invention relates to Diffractive Optical Element (DOE), particularly to a specific dynamic image device using a DOE. This invention is suitable for applications such as stage lighting, decorative lighting, foot light, hand-held lighting rod, scenery light, underwater light, sidewalk light, indoor decoration light, outdoor light, etc.
(2) Brief Description of Related Art
Traditional dynamic image display system using LED panel which is expensive and complicated. Traditional DOE is used to display a static image as shown in FIG. 4. FIGS. 1-3 are three examplified invisible images.
FIG. 1 shows a first invisible image. An invisible image F is imbedded in a diffractive optical element 10. A seesaw display plank 12 is supported by a fulcrum 14. In the position shown in FIG. 1, the A end of the seesaw plank is tilted upward and the B end is tilted downward.
FIG. 2 shows a second invisible image. A second position of the display panel 12, where the seesaw plank 12 is in a horizontal position with A end and the B end at the same level.
FIG. 3 shows a third invisible image. A third position of the display panel 12, where the seesaw plank 12 has the B end tilted above the A end. This position corresponds to a third color.
FIG. 4 shows a prior art optical system utilizing diffractive optical elements 10 shown in FIGS. 1, 2, 3 to produce only a static image.
Different invisible images are inscribed in the DOE by laser tool, but are not changeable or programmable once inscribed.
An object of this invention is to produce a specific dynamic imaging system, where the image can have motion. Another object of this invention is to produce a dynamic color display. Still another object of this invention is to provide a specific dynamic imaging system, which can be maintained easily.
This invention uses a DOE to create a simple specific image display system. These objects are achieved by embodying a plurality of different invisible images in the diffractive optical element DOE. Different images can be displayed when emitted by monochromatic light source at different positions. Dynamic image can be displayed by controlling the light intensity and on/off of the light sources at different positions. This invention is a simple and inexpensive specific dynamic image device which can be used in decoration or business advertisements where only few dynamic images can satisfy.